Innovative product and production optimisation with powder bed technology
With its focus firmly placed on practical requirements, DMG MORI developed the second generation of the LASERTEC 30 SLM machines jointly with NHW 3D as part of a field trial program.
The model and mould making company HFM, the Neher Group, a manufacturer of precision tools, and w3 GmbH, a media service provider, merged in the year 2016 to establish NHW 3D GmbH. This led to the creation of a competence centre for additive processes in Ostrach in southern Germany. Its team of three optimises production processes for customers from the automotive, aerospace and mechanical engineering sectors and develops customised solutions from the idea to prototype construction and on through to preparation for series production. Its range of technical expertise includes plastic laser sintering, stereolithography and metal laser melting. After extensive field trials undertaken in cooperation with DMG MORI, NHW 3D has now expanded the possibilities and capacities in this third field with the procurement of a LASERTEC 30 SLM 2nd Generation.
“3D printing is an efficient solution for the production of complex components”, is how Michael Schmid, CEO of NHW 3D explains the core competence of his company. In particular the additive manufacture of metal components is growing in importance. “This is also true today for small series.” The products manufactured by NHW 3D range from zero series models for gauge and test equipment construction in the automotive industry to 3D-designed or scanned and subsequently optimised single items such as architectural models and on to include internally-cooled drilling and milling tools.
Around 30 % lighter tools thanks to SLM technology
The example of a milling cutter, which NHW 3D produces for the Neher Group, clearly illustrates the benefits of additive production. The cutter is built up on an HSK holder of hot-work steel. A sturdy support structure in the interior of the cutter ensures the necessary torsional stiffness. “The result is a 700 g tool that is 30 percent lighter, but still has the same degree of stability”, says Michael Schmid. Added to this are filigree and conformal cooling channels. “We arrange these in such a way that the jet of coolant hits the cutting edge at the ideal angle.” Even tools with vibration-damping properties or MQL tools can be produced by means of SLM technology. One example of this is the arbor cutter NEHMO DUAL, also developed jointly with the Neher Group, which transports both conventional cooling lubricant and MQL reliably to the cutting edge.” Such optimisations are the result of intensive cooperation in product development.
Michael Schmid is convinced that additive approaches will gain more and more ground in development: “We achieve great savings potential with 3D printing, while shorter development times offer greater flexibility in the product development process.” Cooling channels such as those in the cutter could not be produced with conventional methods, but 3D printing is also a good complement to conventional process chains: “This applies in particular to one-offs required at short notice”, explains Michael Schmid. In many cases design, programming and complex milling operations can be more time and cost-intensive than additive manufacturing.
Win-win situation: Process reliability and maximum availability thanks to joint development
NHW 3D has experienced strong growth since its foundation, so its production capacity had to be increased quickly. The aim of the competence centre for additive processes is also to intensively support the development of the corresponding manufacturing technologies. This led to close cooperation between DMG MORI and NHW 3D in the joint development of the latest generation of the LASERTEC 30 SLM machines within the framework of a field trial program. The motivation of the NHW 3D team led just as much to the cooperation as its entrepreneurial background, recalls the CEO: “We can draw on an extensive range of manufacturing technologies at HFM and the Neher Group was also a development partner of DMG MORI in the past.”
The results of the development partnership reflected in the many practical details of the LASERTEC 30 SLM 2nd Generation have made a lasting impression on NHW 3D. Its fast modular powder changeover system, which DMG MORI calls rePLUG, is a huge bonus. “The powder is in a closed module that can be replaced with a different module in less than two hours”, says Isabel Koschmieder about the changeover procedure. She has been part of the team at NHW 3D since qualifying as a technical model maker at HFM. rePLUG also contributes to safety at work: “The closed material circuit means the potentially reactive cannot escape and be inhaled.”
With regard to the filter system DMG MORI has also taken the question of process reliability into consideration in the LASERTEC 30 SLM 2nd Generation, as Christian Bender, responsible for additive technologies and sales at NHW 3D, explains: “The machine has a powerful duo-filter system that automatically alternates the filters, so filters can be changed without interrupting the process. Other machines would stop until the filter is changed. This boosts the availability of the LASERTEC 30 SLM 2nd Generation significantly, especially at night and weekends.”
Ergonomic operation of the LASERTEC 30 SLM 2nd Generation is also reflected in the control: The latest version is equipped with the uniform control and user interface CELOS. “The machine is a completely open system. In other words, all machine settings and process parameters can be adapted individually”, says Christian Bender, giving us an insight into the day-to-day use of the machine. This ensures flexibility in production as well as an unlimited choice of material suppliers.
“The LASERTEC 30 SLM 2nd Generation allows us to optimise existing manufacturing processes intelligently with innovative ideas”
Another advantage of the LASERTEC 30 SLM 2nd Generation comes into play with regard to the limited production area at NHW 3D. “The compact design is worth its weight in gold”, says Michael Schmid. There is the possibility of moving the company into larger premises in the long term. “That would be a logical step as the company continues to grow, so we could expand our capacity accordingly.”
The prospects for further growth are indeed excellent. The company has gained some of its 40 customers via HFM, Neher and w3: “However, we were able to acquire many customers in the conventional way by impressing them with our range of products and services”, Michael Schmid is pleased to tell us. He sees personal contact and the optimisation of production processes as the formula for success: “Our aim is to optimise production processes intelligently with innovative ideas and to print perfect components. The new LASERTEC 30 SLM 2nd Generation plays a key role here.”